using System;
using System.Collections.Generic;
using System.Linq;

using FrostFS.Object;

using FrostFS.SDK.ClientV2.Mappers.GRPC;

namespace FrostFS.SDK;

public class FrostFsObjectHeader(
    FrostFsContainerId containerId,
    FrostFsObjectType type = FrostFsObjectType.Regular,
    FrostFsAttribute[]? attributes = null,
    FrostFsSplit? split = null,
    FrostFsOwner? owner = null,
    FrostFsVersion? version = null)
{
    private Header header;
    private Container.Container.Types.Attribute[]? grpsAttributes;
   
    public List<FrostFsAttribute> Attributes { get; internal set; } = attributes != null ? [.. attributes] : [];

    public FrostFsContainerId ContainerId { get; } = containerId;

    public ulong PayloadLength { get; set; }

    public byte[]? PayloadCheckSum { get; set; }

    public FrostFsObjectType ObjectType { get; } = type;

    public FrostFsOwner? OwnerId { get; internal set; } = owner;

    public FrostFsVersion? Version { get; internal set; } = version;

    public FrostFsSplit? Split { get; internal set; } = split;

    internal Container.Container.Types.Attribute[]? GetGrpsAttributes()
    {
        grpsAttributes ??= Attributes?
            .Select(a => new Container.Container.Types.Attribute { Key = a.Key, Value = a.Value })
            .ToArray();

        return grpsAttributes;
    }

    public Header GetHeader()
    {
        if (header == null)
        {
            var objTypeName = ObjectType switch
            {
                FrostFsObjectType.Regular => Object.ObjectType.Regular,
                FrostFsObjectType.Lock => Object.ObjectType.Lock,
                FrostFsObjectType.Tombstone => Object.ObjectType.Tombstone,
                _ => throw new ArgumentException($"Unknown ObjectType. Value: '{ObjectType}'.")
            };

            this.header = new Header
            {
                OwnerId = OwnerId?.ToMessage(),
                Version = Version?.ToMessage(),
                ContainerId = ContainerId.ToMessage(),
                ObjectType = objTypeName,
                PayloadLength = PayloadLength
            };

            foreach (var attribute in Attributes)
            {
                this.header.Attributes.Add(attribute.ToMessage());
            }

            var split = Split;
            if (split != null)
            {
                this.header.Split = new Header.Types.Split
                {
                    SplitId = split!.SplitId != null ? split.SplitId.GetSplitId() : null
                };
            }
        }

        return this.header;
    }
}